Compact sensing apparatus having reduced cross section and methods of mounting same

ABSTRACT

A compact sensing apparatus having reduced cross section and methods are provided for sensing the magnitude and direction of an electrical or magnetic field. The compact sensing apparatus and method preferably provide one of two transducer orientations in relation to the direction of the field arranged in the sensor apparatus to provide the smallest possible cross section. The compact sensing apparatus preferably includes a plurality of mounting pins. Each of the plurality of mounting pins preferably includes a first pin portion and a second pin portion connected to the first pin portion at a predetermined angle. The predetermined angle is preferably less than 180 degrees and more preferably in the range of about 70-110 degrees. A transducer formed from a semiconductor wafer is preferably mounted to the first pin portion for generating a transducer signal, and a signal conditioner also preferably formed from the same semiconductor wafer is mounted to the second pin portion for conditioning the transducer signal.

RELATED APPLICATIONS:

This patent application is a continuation of U.S. Ser. No. 09/321,191filed May 27, 1999 U.S. Pat. No. 6,181,609, which is a divisional ofU.S. Ser. No. 08/954,196 filed Oct. 20, 1997, now U.S. Pat. No.6,002,252, which is a continuation-in-part of U.S. Ser. No. 08/760,104filed Dec. 3, 1996, now U.S. Pat. No. 5,738,071, which is acontinuation-in-part of U.S. Ser. No. 08/471,192 filed Jun. 7, 1995, nowU.S. Pat. No. 5,670,886, which is a continuation-in-part of U.S. Ser.No. 07/703,269 filed May 22, 1991, now U.S. Pat. No. 5,459,405.

FIELD OF THE INVENTION

The present invention relates to the field of sensors and, moreparticularly to the fields of sensors and methods of mounting sensors.

BACKGROUND OF THE INVENTION

Over the years sensors have been developed which include transducersthat possess a specific preferred orientation in relation to anelectrical field, a magnetic field, or a mechanical force to be sensed.To maximize the response of the sensor, the transducer must be orientedin the direction of this field or force. Some examples of electrical ormagnetic field sensors are position and proximity sensors such as Halleffect, magnetoresistor, capacitive, and inductive sensors andelectrical current field sensors. Mechanical force sensors generallymeasure the flow or pressure of a liquid or gas, the mechanical stressor weight of an object, or the acceleration of an object. These sensorsgenerally have a preferred orientation of the transducer to theelectrical or magnetic field or to the physical force being sensed inorder to maximize the sensitivity of the transducer.

Also, there may be other extraneous electrical or magnetic fields ormechanical forces in the system. The transducer may have to be orientedrelative to these extraneous fields or forces in a specific direction toreduce the sensitivity of the transducer to them. This helps toeliminate sensing errors or noise caused by the movement of otherobjects or caused by the presence of other fields or forces.

These sensors also conventionally employ signal conditioning circuitryor a signal conditioner to amplify or otherwise condition the transducersignal. The signal conditioner is needed, for example, because thetransducer signal is usually too low in magnitude to overcome noise orcontains a large offset or other error signals that overdrive sensitivemonitoring equipment. Otherwise, the transducer signal is not conduciveto transmission over a distance to a remotely located sensor monitoringcircuit.

Additionally, the sensors are often used in mechanical systems that haverestrictions on overall size, weight, structural integrity, reliability,and cost. For these reasons, the sensor is usually made as small aspossible by using transducers and signal conditioners that areelectronic or that contain electrical devices manufactured onsemiconductor wafers.

A first significant problem with transducers and signal conditionerswhich are manufactured as semiconductor devices, however, is that theelectrical conductivity or other operating characteristics changesignificantly in response to changes in temperature. This can result ina significant change in transducer output as a function of temperature.Because most of the mechanical systems in which these sensors operatecan experience rather significant changes in operating temperature, theeffects of these temperature changes on the sensor output constitutes anerror signal and should therefore be eliminated or reduced if possible.

The elimination of this error signal is usually a function of the signalconditioner and is usually accomplished in several related ways. Thetransducer and signal conditioner that are to be used together in anysingle sensor are usually manufactured at the same time using the samemanufacturing process and are located as closely as possible in relationto each other on the same semiconductor wafer. This is done primarily tomake the physical proportions of the components that comprise thetransducer and the signal conditioner equal or proportional in width,length, and depth of features and to have equal relative concentrationsof the various semiconductor materials used to form the components. Forinstance, all transistor bases, emitters, and collectors will beessentially the same relative size even if they are manufacturedslightly larger or smaller than intended, and will have generally thesame concentrations of materials regardless of whether they are at theintended levels of these various concentrations. The electricalconductivity of any particular electrical component in the transducer orthe signal conditioner is proportional to the size of its features aswell as the concentration of materials from which the component ismanufactured. Any two components on the wafer located in close proximityto each other with the same dimensions and formed from the same relativeconcentrations of materials generally will have equal electricalconductivities if they are at the same temperature. Also, any componentlocated near another component which has the same concentrations ofmaterials but whose dimensions are not equal but are proportional to theother component will have an electrical conductivity that isproportional in the same degree as the dimensions if they are both atthe same temperature. Because the size and composition of thesecomponents are set during manufacture, any short term changes in theirelectrical conductivity under identical electrical conditions aregenerally caused only by changes in the temperature of the component.

In this manner any specific component or collection of components on thetransducer required for proper operation can be duplicated in the signalconditioner at the same size or at a specific proportional scale andwith equal concentrations of materials. For example, some transducersemploy four resistors in a Wheatstone bridge configuration. Any one ormore of these resistors can be made with equal dimensions and with equalcomposition of materials on the signal conditioner. Under theseconditions, the electrical conductivity of both pairs of resistorsgenerally will be equal if their temperatures are equal. In any case, ifthe temperature of the transducer components is the same as thetemperature of the signal conditioner components, both the transducerand signal conditioner will contain components that experience equal orproportional electrical conductivity due to the effects of temperaturealone.

One of two methods are generally used in association with a signalconditioner to determine this change in electrical conductivity and thento produce a corresponding signal that cancels the effects of thischange on the transducer output. First, if size allows, a completeduplicate of the transducer can be made on the signal conditioner. Thisduplicate transducer is then electrically, magnetically, or physicallyshielded from the field or force being sensed or is in some manner madeunresponsive to the sensed parameter. An equal excitation or drivesignal is then applied to both the components comprising the activetransducer and the components comprising the duplicate passivetransducer on the signal conditioner. The output of the signalconditioner passive transducer is then relative only to temperature andis then subtracted from the output of the active transducer thatresponds to the field or force. This is usually accomplished in adifferential amplifier or a similar electronic circuit.

A second method, for example, can be used where space for the signalconditioner is more limited. A representative part of the transducer atany proportion can be duplicated on the signal conditioner. Thisrepresentative part can be chosen to be a part that is unresponsive tothe parameter being sensed or can be physically oriented to a positionwhere it is not affected or otherwise shielded from the parameter beingsensed. In any case, it is designed so its electrical conductivity isproportional only to changes in temperature. The change of thetransducer output due to the cumulative changes of electricalconductivity of all transducer components due only to changes intemperature is determined by direct measure or by mathematicalcalculation during the sensor design phase. This yields a specific levelof transducer output change per degree of change in temperature. Thisinformation is used to design a circuit with a specific amount of gaindetermined by the relationship of the change in electrical conductivityof the signal conditioner duplicate component to the change intransducer output caused by a change in temperature. This circuitmonitors the change in electrical conductivity of the signal conditionerduplicate component and then amplifies this change by the amountrequired to yield an equivalent signal level change that is thensubtracted from the transducer output as above.

Long term changes of electrical conductivity are a second significantproblem in semiconductor components. This is usually caused byelectromigration of the atoms of the material comprising the componentsfrom their positions as manufactured along paths of electrical currentinto areas that are not designed to contain them. For instance, theatoms comprising the base structure of a transistor can migrate into theareas occupied by the emitter and the collector, and vice versa. Thischanges both the physical size of the component as well as itsconcentration of the materials comprising the component. Any componentin the transducer will experience these effects the same as an identicalcomponent in the signal conditioner provided the current through bothcomponents is kept equal over the life of the sensor. This is felt thesame way as the short term effects of temperature as above by bothcomponents in the transducer and in the signal conditioner and is thuseffectively compensated for in the same manner as short term changes intemperature.

During the manufacturing process, both the transducer and the signalconditioner are formed on a common surface on the wafer known as theplanar surface. Since components are not usually formed on top of othercomponents, this results in transducers and signal conditioners thathave a large surface area relative to the depth of the devices. The areataken up by these devices is generally measured along this planarsurface. The depth of all such semiconductor devices is usually fixed bydesign considerations and is not relative to the number of devices.

Prior art sensors generally manufacture the signal conditioner andtransducer on the same wafer and interconnect the two using conductivetraces defined directly on the wafer. The prior art sensors are theninstalled as a single monolithic chip in the sensor. Since thetransducer generally should be oriented in a specific direction relativeto the field being sensed, this requires that the signal conditioner beoriented also to the field in like manner.

Also, the amount of area occupied by the transducer is much smaller thanthe area occupied by the signal conditioner. Orientation of both atransducer and a signal conditioner along the same plane generallyproduces a larger cross section for the sensor than could be achieved byorienting the transducer to the field and orienting the signalconditioner separately in whatever direction needed to realize thesmallest cross section. Because the signal conditioner does not requirea specific orientation in relation to the field, a much smaller crosssection in relation to a specific direction of measurement can berealized by changing the orientation of the transducer and signalconditioner so they are orthogonal. This can only be accomplished if thetransducer and signal conditioner are physically separated andelectrically connected using some means other than the conductive tracesso the transducer can be oriented to the field or force separately fromthe signal conditioner.

SUMMARY OF THE INVENTION

With the foregoing in mind, the present invention advantageouslyprovides a compact sensing apparatus that achieves a smallest crosssection in relation to a defined axis. The present invention alsoadvantageously provides a compact sensing apparatus and method whichsimplify manufacture of a sensing apparatus or sensor by providing meansfor orienting the transducer in a selected direction in relation to thesignal conditioner.

The present invention accomplishes these objects and advantages relatingto field orientation by positioning a transducer in a specificorientation relative to a signal conditioner in a sensing apparatus. Thetransducer and signal conditioner can be manufactured simultaneously ona semiconductor wafer and means are employed to either leave thetransducer and signal conditioner oriented as manufactured or to arrangethem physically at right angles to each other to provide the maximumsensitivity to the field for the transducer and the minimum crosssection for the sensing apparatus along its axis of orientation.

The present invention also accomplishes the objects and advantages ofthe orientation of the transducer and signal conditioner by employingelectrically conductive pins that are rigid. The pins provide electricalconnection between the transducer and the signal conditioner and betweenthe signal conditioner and external sensor monitoring equipment.

More particularly, a compact sensing apparatus according to the presentinvention preferably includes plurality of mounting pins. Each of theplurality of mounting pins preferably includes a first pin portion and asecond pin portion connected to the first pin portion at a predeterminedangle. The first pin portion preferably has a length less than thesecond pin portion, and the predetermined angle is preferably less than180 degrees and more preferably in the range of about 70-110 degrees. Atransducer is formed from a semiconductor wafer mounted to the first pinportion for generating a transducer signal. Signal conditioning meansalso is formed from the same semiconductor wafer and mounted to thesecond pin portion for conditioning the transducer signal.

A compact sensing apparatus according to another aspect of the presentinvention preferably includes a plurality of mounting pins. Each of theplurality of mounting pins includes a first pin portion and a second pinportion connected to the first pin portion at a predetermined angle. Thefirst pin portion preferably has a length less than the second pinportion. A transducer is mounted to the first pin portion for generatinga transducer signal. A signal conditioner is mounted to the second pinportion for conditioning the transducer signal. The signal conditioneris preferably mounted to the second pin portion so that the lateralextent of the signal conditioner is generally perpendicular to thelateral extent of the transducer.

According to other aspects of the present invention, a compact sensingapparatus has the plurality of mounting pins which are defined by aplurality of spaced-apart and elongate mounting pins. The lengthwiseextent of each of the plurality of spaced-apart and elongate mountingpins is spaced-apart from and generally parallel to the lengthwiseextent of another one of the plurality of pins. The plurality ofspaced-apart and elongate mounting pins include a plurality of generallycoaxially aligned and laterally spaced-apart mounting pins. Each of thelaterally spaced-apart portions extending between the generallycoaxially aligned mounting pins is positioned at a different lengthwiseextending location than another generally parallel and spaced apartplurality of elongate mounting pins so that at least two of thelaterally spaced-apart portions define a plurality of staggered gapsextending between the generally coaxially aligned mounting pins. Theplurality of staggered gaps thereby advantageously form electricalisolation between the plurality of generally coaxially aligned mountingpins and thereby increase the stiffness of the sensing apparatus. Theplurality of mounting pins are each formed of an electrically conductiverigid material and positioned so as to define electrical connectors forthe transducer and the signal conditioning means and to provide physicalsupport for the transducer and the signal conditioning means mountedthereto.

Additionally, each of the transducer and the signal conditioning meansare preferably formed on the same surface, e.g., the upper surface, ofthe same semiconductor wafer substrate. A plurality of bonding pads arealso formed on the upper surface of the same semiconductor wafersubstrate for bonding the transducer and the signal conditioning meansto the plurality of mounting pins. Also, a plurality of conductivetraces are preferably formed in the same substrate to provide conductivepaths between the transducer and the signal conditioning means. Thetransducer can include a planar surface for more sensitively sensing afield having flux lines extending either generally perpendicular to theplanar surface or generally parallel to the planar surface.

According to still another aspect of the present invention, the firstand second pin portions of each of the plurality of mounting pins of thecompact sensing apparatus preferably is a single unitary pin. The singleunitary pin preferably includes a bend formed therein having an angle ofbend defining the predetermined angle of orientation of the first andsecond pin portions. The transducer can also include a channel formedclosely adjacent an edge thereof for adaptively positioning thetransducer closely adjacent the bend so that the transducer adaptivelyclears the bend of each of the plurality of mounting pins. Thetransducer advantageously can be connected to either a forwardlyextending surface of the first pin portion which extends away from thesignal conditioning means or to a rearwardly extending surface of thefirst pin portion which extends toward said signal conditioning means orto either of two surfaces on the second pin portion.

The present invention also includes methods of compactly mounting asensing apparatus. The method preferably includes the steps of forming atransducer and a signal conditioner from the same semiconductor waferand providing at least two mounting surfaces. The at least two mountingsurfaces are oriented with respect to each other at a predeterminedangle. The predetermined angle is preferably less than 180 degrees andmore preferably is in the range of about 70-110 degrees. The method alsoincludes connecting the transducer to one of the at least two mountingsurfaces and connecting the signal conditioner to another one of the atleast two mounting surfaces.

Another method of compactly mounting a sensing apparatus according tothe present invention preferably includes providing a transducer and asignal conditioner and positioning the signal conditioner so that thelateral extent thereof is generally perpendicular to the lateral extentof the transducer. The transducer and the signal conditioner are eachrespectively mounted on at least two mounting surfaces. The at least twomounting surfaces are preferably oriented with respect to each other ata predetermined angle.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the features, advantages, and benefits of the present inventionhaving been stated, others will become apparent as the descriptionproceeds when taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is an isometric view of a transverse transducer showing relativeorientation of the field being sensed in relation to the planar surfaceof the transducer of a compact sensing apparatus according to a firstembodiment of the present invention;

FIG. 2 is an isometric view of an orthogonal transducer showing relativeorientation of the field being sensed in relation to the planar surfaceof the transducer of a compact sensing apparatus according to a secondembodiment of the present invention;

FIG. 3 is an isometric view of an orthogonal transducer and signalconditioner on the same planar surface of an integrated circuit chip ofa compact sensing apparatus according to a second embodiment of thepresent invention;

FIG. 4 is an isometric view of a transverse transducer and signalconditioner on the same planar surface of an integrated circuit chip ofa compact sensing apparatus according to a first embodiment of thepresent invention;

FIG. 5 is an isometric view of a compact sensing apparatus with anorthogonal transducer and signal conditioner arranged for minimal crosssection according to a second embodiment of the present invention;

FIG. 6 is an isometric view of a compact sensing apparatus with anorthogonal transducer and signal conditioner arranged for minimal crosssection according to a second embodiment of the present invention;

FIG. 7a is a top plan view of a transducer and a signal conditionerformed on the same semiconductor wafer of a compact sensing apparatusaccording to embodiments of the present invention;

FIG. 7b is a side elevational view of a transducer and a signalconditioner formed on the same semiconductor wafer of a compact sensingapparatus according to embodiments of the present invention;

FIG. 8 is an isometric view of a plurality of mounting pins used toelectrically connect a transducer and a signal conditioner of a compactsensing apparatus according to embodiments of the present invention;

FIG. 9 is an isometric view of the formation of insulating material usedto prevent electrical shorts and to hold a plurality of mounting pins inplace for a compact sensing apparatus according to embodiments of thepresent invention;

FIG. 10 is an isometric view of a compact sensing apparatus whichillustrates the arrangement of a plurality of mounting pins, atransducer, and a signal conditioner for a sensing apparatus with thetransducer positioned generally orthogonal to the signal conditioner ona sensing apparatus according to another alternative embodiment of thepresent invention; and

FIG. 11 is an isometric view of a compact sensing apparatus whichillustrates the arrangement of a plurality of mounting pins, atransducer, and a signal conditioner for a sensing apparatus with thetransducer positioned generally orthogonal to the signal conditioner ona sensing apparatus for operation according to yet another embodiment ofthe present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings which illustrate preferredembodiments of the invention. This invention may, however, be embodiedin many different forms and should not be construed as limited to theillustrated embodiments set forth herein. Rather, these illustratedembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the invention to thoseskilled in the art. Like numbers refer to like elements throughout, theprime notation, if used, indicates similar elements in alternativeembodiments.

FIGS. 1-2 illustrate field sensing transducers 22,22′ including planarsurfaces 24, 24′ and electric or magnetic fields 26, 26′ of a compactsensing apparatus according to first and second embodiments of thepresent invention. For simplicity, the field sensing transducers 22, 22′will be referred to as transducers 22, and electric or magnetic fields26, 26′ will be referred to simply as fields 26. As understood by thoseskilled in the art, there are numerous types of transducers 22 thatsense the presence or magnitude of electrical or magnetic fields 26which can be used in the compact sensing apparatus of the presentinvention. These transducers 22 are usually fabricated on semiconductorwafers by deposition of material onto the planar surface 24 of thewafer. These transducers 22 generate electrical signals in proportion tothe number of lines of flux of the field 26 that pass through thematerial of the transducer 22 in a preferred direction relative to thetransducer's planar surface 24.

Some transducers 22, however, are more sensitive to fields 26 that aregenerally parallel to this planar surface 24, and others are moresensitive to fields 26 that are generally perpendicular to the planarsurface 24. Also for simplicity, the transducers 22 whose preferredfield 26 direction is generally perpendicular to the planar surface 24will be referred to as orthogonal transducers 22, and transducers 22whose preferred field 26 direction is generally parallel to the planarsurface 24 will be referred to as transverse transducers 22.

An example of a transverse transducer 22 that senses fields 26 orientedgenerally parallel to its planar surface 24 is a magnetoresistor.Examples of orthogonal transducers 22 that sense fields 26 orientedgenerally perpendicular to their planar surfaces 24 are magnetic sensorssuch as Hall effect cells and electrical sensors such as capacitivetransducers 22. A difference between these two sensors, for example, isthat the Hall effect cell detects magnetic fields and the capacitivetransducer detects electrical fields.

FIG. 1, on the one hand, illustrates the field 26 of a transversetransducer 22, or one with maximum sensitivity attained when the field26 is generally parallel or transverse to the planar surface 24 of thetransducer 22. FIG. 2, on the other hand, shows the field 26 of anorthogonal transducer 22, or one with maximum sensitivity when the field26 is generally perpendicular or orthogonal to the planar surface 24 ofthe transducer 22. As understood by those skilled in the art, numerousother types of transverse and orthogonal transducers 22 also exist andcan be used according to the present invention. Specifically, these maybe inductive sensors, planar antenna arrays, light transducers, or anyother electromagnetic sensor. In like manner, transducers that respondto physical forces in a preferred direction, such as micro-machinedpressure sensors, flow sensors, or accelerometers also can be configuredfor a minimum cross section 34 according to the present invention. Inexamples of sensors that sense physical forces, the lines of flux of thefield 26 can be considered to be the lines of the force or forces beingsensed for the purposes of this invention.

FIG. 3 illustrates an arrangement of an orthogonal transducer 22 andsignal conditioning means, e.g., preferably provided by a signalconditioner 28 or signal conditioning circuitry, formed on the planarsurface 24 of a semiconductor wafer in relation to a target 30, a field26, a sensor cross section 34, and a sensor axis 36 for a compactsensing apparatus 32 with the transducer 22 and the signal conditioner28 joined as manufactured on the wafer. For the purposes of thisdiscussion, the target 30 will be considered to be any object thateither generates fields 26 or forces or that by changes in physical orelectromagnetic properties causes a change in the magnitude or fluxdensity of the field 26 or the forces at the planar surface 24 of thetransducer 22. Also, for the purposes of this description, the crosssection 34 of the compact sensing apparatus 32 is defined to begenerally perpendicular to the sensor axis 36. The sensor cross section34 is further defined to be the diameter of the smallest circleencompassing all parts of the sensor 32 drawn at a right angle to thesensor axis 36.

Generally, the least expensive method of mounting a sensing apparatus 32in a mechanical or electrical system is to drill a hole in a desiredmounting structure and secure the sensing apparatus 32 in the hole. Inmost systems, the hole must be kept as small as possible to decreasemanufacturing costs, to reduce the size of the system as much aspossible, and to provide the maximum possible amount of materialsurrounding the hole in order to provide the maximum mechanicalstiffness for the system. To make this hole as small as possible, thecomponents of the sensing apparatus 32 preferably should be arranged toprovide the smallest cross section 34 for the sensing apparatus 32 whenthe sensor axis 36 is aligned with the central axis of the hole.

Often, the signal from the transducer 22 is too weak to overcomeexternal noise, is changed significantly by changes in temperature,contains a large offset, or in some other manner is inadequate fordirect connection to remote sensor monitoring equipment. In these casesthe signal is modified by a signal conditioner 28 which is preferablyplaced as closely as possible to the transducer 22. To allow the signalconditioner 28 to best compensate for changes in transducer 22 signallevels due to changes in temperature, the signal conditioner 28 andtransducer 22 are preferably manufactured on the same semiconductorwafer. In this manner, any process variations encountered during themanufacturing process will cause the changes in temperature to be feltequally by both the transducer 22 and the signal conditioner 28. If thetransducer 22 and signal conditioner 28 are kept at the sametemperature, this allows the signal conditioner 28 to cancel the effectsof transducer 22 signal change as a result of changes in temperature.For modem microelectronic sensors, this generally means that the planarsurface 24 of the transducer 22 is preferably the same as the planarsurface 24 of the signal conditioner 28.

FIG. 3 shows the arrangement of a compact sensing apparatus 32 employingan orthogonal transducer 22 arranged to monitor a target 30 thatgenerates or modifies a field 26 that is parallel to the sensor axis 36.Note that if the signal conditioner 28 and transducer 22 aremanufactured as a single chip as shown, this arrangement results in across section 34 that includes the area required by both the transducer22 and the signal conditioner 28. This results in a significantly largercross section 34 than would be required for the transducer 22 alone.

FIG. 4 illustrates an arrangement of a compact sensing apparatus 32utilizing a transverse transducer 22 to monitor a field 26 parallel tothe sensor axis 36. Note that the cross section 34 for this arrangementis significantly smaller than the cross section 34 for the sensingapparatus 32 shown in FIG. 3. FIG. 5, on the other hand, illustrates amethod of arranging or compactly mounting an orthogonal transducer 22and signal conditioner 28 to realize the smallest possible cross section34 for the sensing apparatus 32. This is accomplished by physicallyseparating the transducer 22 and signal conditioner 28 and then mountingthe signal conditioner 28 so its planar surface 24 is positionallyaligned with the sensor axis 36.

FIG. 6 illustrates an arrangement for an orthogonal transducer 22employed to sense a field 26 that is perpendicular to the sensor axis36. Note this method of arrangement does not differ from the arrangementshown in FIG. 3 except that the transducer 22 and signal conditioner 28chips are two separate objects. This allows the transducer 22 to befabricated from different semiconductor materials or in a differentprocess than the signal conditioner 28. If the transducer 22 and signalconditioner 28 are manufactured on the same semiconductor wafer, thearrangement shown in FIG. 3 is preferred because it requires fewermanufacturing steps.

FIGS. 7a and 7 b respectively are a top plan view and a side elevationalview of the formation of a sensing apparatus 32 on the planar surface 24of a semiconductor wafer. Note that although only one chip is shown,many such identical chips are formed on the same wafer simultaneously.Note also that the chip is shown after being cut apart from each othersensor or transducer chip so formed on the wafer. The transducer 22 andsignal conditioner 28 are formed on the planar surface 24 usingsemiconductor fabrication techniques well known in the art.Additionally, conductive traces 38 are formed to provide electricalconnection between the transducer 22 and the signal conditioner 28 andbetween the signal conditioner 28 and the remote sensor monitoringequipment. Before these conductive traces 38 are applied, however, anetched channel 42 is preferably formed by masking and etching processesas understood by those skilled in the art. Bond pads 40 are added toprovide electrical connection to other devices or between the transducer22 and signal conditioner 28 if they are to be separated (also note theoptional cutting path 44). If the sensing apparatus 32 is to befabricated as a single monolithic device as shown in FIG. 4, this cut isnot made. If the transducer 22 is to be oriented as shown in FIG. 5 orFIG. 6, however, the transducer 22 and signal conditioner 28 are cutapart along the line shown.

FIG. 8 is an isometric view of a plurality of spaced-apart and elongatemounting pins 46 used to connect the transducer 22 to the signalconditioner 28 and to connect the signal conditioner 28 to externalsensor monitoring equipment. Each of the plurality of mounting pins 46preferably include a first pin portion and a second pin portionconnected to the first pin portion at a predetermined angle. Asillustrated, the first pin portion preferably has a length less than thesecond pin portion, but this may vary depending on the staggered gaps,for example, as described further below herein. The predetermined angleis preferably in the range of about 70-110 degrees, and moreparticularly at about right angles, e.g., 85-95 degrees. The transducerformed from a semiconductor wafer is preferably mounted to the first pinportion for generating a transducer signal. The signal conditioner,preferably formed from the same semiconductor wafer as the transducer,is preferably mounted to the second pin portion for conditioning thetransducer signal (see also FIGS. 10-11).

The lengthwise extent of each of the plurality of spaced-apart andelongate mounting pins 46 is preferably spaced-apart from and generallyparallel to the lengthwise extent of another one of the plurality ofpins 46. The plurality of mounting pins 46 include a plurality ofgenerally coaxially aligned and laterally spaced-apart mounting pins.Preferably, as illustrated, at least two of the mounting pins 46, or pinportions, turn at approximate right angles to connect the transducer 22to the signal conditioner 28, and at least two of the mounting pins arerelatively straight to connect the signal conditioner 28 to externalsensor monitoring equipment. Each of the laterally spaced-apart portionsextending between the generally coaxially aligned mounting pins ispositioned at a different lengthwise extending location than anothergenerally parallel and spaced apart plurality of elongate mounting pinsso that at least two of the laterally spaced-apart portions define aplurality of staggered gaps 48 extending between the generally coaxiallyaligned mounting pins. The plurality of staggered gaps 48 thereby formelectrical isolation between the plurality of generally coaxiallyaligned mounting pins and thereby increase the stiffness of the sensingapparatus. These gaps are staggered so they are not both in the sameplane that is orthogonal to the sensor axis 36 to provide mechanicalsupport for or increase the stiffness of the sensing apparatus 32 so itis less likely to bend along the sensor axis 36.

As perhaps best illustrated in FIG. 9, insulation 50 is preferablyapplied to the pins 46 on all areas that do not require a directelectrical path to the transducer 22, the signal conditioner 28, or toexternal monitoring equipment. Since the insulation 50 is usually notrigid, the staggered gaps 48 between the pins 46 still serve to helpprevent the sensor connector 52 from bending during manufacture.

In some sensor applications, the magnetic field 26 changes moresignificantly for a given set of operating parameters when a magnet isplaced behind the transducer 22 relative to the target 30. For theseapplications, FIG. 10 illustrates the arrangement of a transducer 22 andmounting pins 46 according to an alternative embodiment of a sensingapparatus 32. Here the transducer 22 has its planar surface 24 rotatedand placed against the pins 46 at a point closest to the target 30. Anelectrical connection is made to the bond pads 40 and mechanical supportfor the chips is realized through the use of conductive epoxies, solderbumps, or some other appropriate method as understood by those skilledin the art. In these applications the field 26 penetrates the transducer22 from the side opposite its planar surface 24. This arrangement alsomakes the transducer 22 as sensitive to the field 26 as possible byplacing the planar surface 24 of the transducer 22 as close as possibleto the target 30 or to the source of the field 26.

According to another embodiment a sensing apparatus 32 and associatedmounting method are shown in FIG. 11. This arrangement places thetransducer 22 so that the pins 46 are between the target 30 and thetransducer 22. This arrangement is generally used where the field 26 ismore advantageously modified by the pins 46 being in this position;where the transducer 22 planar surface 24 is to be protected by the pins46; or where more precise mechanical alignment of the transducer 22 isdesired. Since the pins 46 generally have some small but finite innerbend radius, the etched channel 42 serves to form a void between thetransducer 22 and the pins 46 to allow the transducer 22 to fit flushagainst the pins 46 along the flat surface of the pins 46 withoutinterference.

For either of the embodiments of a sensing apparatus 32 described abovewith reference to FIG. 10 or FIG. 11, the signal conditioner 28 ispreferably placed in the position shown. It is mechanically attached andelectrically connected to the pins 46 the same way as the transducer 22.Two bond pads 40 preferably connect through the mounting pins 46 to thetransducer 22, and two bond pads 40 connect through the straight pins 46to external monitoring equipment. Neither drawing shows the actualbonding method used because the material used to form the bond isusually applied during chip fabrication and as such is considered anintegral part of the bond pads 40.

Advantageously, a compact sensing apparatus 32 according to the presentinvention as described herein can be used to physically arrange andelectrically connect transducers 22 and signal conditioners 28 or anyother such electrical devices requiring electrical interconnection inthe same basic arrangement shown herein. Also, although only twomounting pins 46 are shown connecting the transducer 22 to the signalconditioner 28, and two mounting pins 46 are shown connecting the signalconditioner to external monitoring equipment, any number of pins or pinportions can be used as required.

As illustrated in FIGS. 1-11, the present invention also includesmethods of compactly mounting a sensing apparatus 32. A method ofmounting according to the present invention preferably includes thesteps of forming a transducer 22 and a signal conditioner 28 from thesame semiconductor wafer and providing at least two mounting surfaces,e.g., on the mounting pins 46. The at least two mounting surfaces areoriented with respect to each other at a predetermined angle. Thepredetermined angle is preferably less than 180 degrees and morepreferably is in the range of about 70-110 degrees. The method alsoincludes connecting the transducer 22 to one of the at least twomounting surfaces and connecting the signal conditioner 28 to anotherone of the at least two mounting surfaces. The method can additionallyinclude the at least two mounting surfaces being mounting surfaces on aplurality of mounting pins 46. Each of the plurality of mounting pins 46includes a first pin portion and a 15 second pin portion connected tothe first pin portion at the predetermined angle. The first pin portionhas a length less than the second pin portion. The connecting steppreferably includes mounting the transducer 22 to a surface of the firstpin portion, and the signal conditioner connecting step includesmounting the signal conditioner 28 to a surface of the second pinportion. The first and second pin portions of each of the plurality ofmounting pins comprise a single unitary pin. The single unitary pinincludes a bend formed therein having an angle of bend defining thepredetermined angle of orientation of the first and second pin portions.Also, a channel 42 is formed in the transducer 22, e.g., preferably byetching, closely adjacent an edge thereof and adaptively positioning thetransducer 22 closely adjacent the bend so that the transducer 22adaptively clears the bend of each of the plurality of mounting pins 46.

The method can further include separating the transducer 22 from thesignal conditioner 28 such as along a preselected cutting path 44 andpositioning the signal conditioner 28 so that the lateral extent thereofis generally perpendicular to the lateral extent of the transducer 22. Aplurality of bonding pads 40 a, 40 b, 40 c, 40 d, 40 e and 40 f can beformed on the same semiconductor wafer also so that the pads serve tomechanically and electrically bond the transducer and the signalconditioner to the mounting surfaces. Also, a plurality of conductivetraces 38 a, 38 b are also formed on the same semiconductor wafer forproviding a conductive path between the transducer 22 and the signalconditioner 28 in the special case wherein the transducer 22 and thesignal conditioner 28 are not physically separated.

Another method of compactly mounting a sensing apparatus 32 according tothe present invention preferably includes providing a transducer 22 anda signal conditioner 28 and positioning the signal conditioner 28 sothat the lateral extent thereof is generally perpendicular to thelateral extent of the transducer 22. The transducer 22 and the signalconditioner 28 are each respectively mounted on at least two mountingsurfaces. The at least two mounting surfaces are preferably orientedwith respect to each other at a predetermined angle such as describedabove herein.

The method can also include connecting the transducer 22 to one of theat least two mounting surfaces and connecting the signal conditioner 28to another one of the at least two mounting surfaces. The at least twomounting surfaces preferably are mounting surfaces on a plurality ofmounting pins 46. Each of the plurality of mounting pins 46 includes afirst pin portion and a second pin portion connected to the first pinportion at the predetermined angle. The first pin portion has a lengthless than the second pin portion. The transducer 22 connecting stepincludes mounting the transducer 22 to a surface of the first pinportion, and the signal conditioner connecting step includes mountingthe signal conditioner 28 to a surface of the second pin portion.

The first and second pin portions of each of the plurality of mountingpins 46 preferably are a single unitary pin, and the single unitary pinpreferably includes a bend formed therein having an angle of benddefining the predetermined angle of orientation of the first and secondpin portions. A channel 42 is also provided for the transducer 22closely adjacent an edge thereof, and the transducer 22 is adaptivelypositioned closely adjacent the bend so that the transducer 22adaptively clears the bend of each of the plurality of mounting pins 46.

The method additionally can include providing a plurality of bondingpads 40 a, 40 b, 40 c, 40 d, 40 e and 40 f for each of the transducer 22and the signal conditioner 28 for bonding the transducer 22 and thesignal conditioner 28 to the mounting surfaces and forming a pluralityof conductive traces 38 a, 38 b for providing a conductive path betweenthe transducer 22 and the signal conditioner 28.

In the drawings and specification, there have been disclosed a typicalpreferred embodiment of the invention, and although specific terms areemployed, the terms are used in a descriptive sense only and not forpurposes of limitation. The invention has been described in considerabledetail with specific reference to these illustrated embodiments. It willbe apparent, however, that various modifications and changes can be madewithin the spirit and scope of the invention as described in theforegoing specification and as defined in the appended claims.

That which is claimed:
 1. A compact sensing apparatus comprising: atransducer formed from a semiconductor wafer, positioned in a firstplane; a signal conditioner formed from the same semiconductor wafer asthe transducer, electrically connected to the transducer, and positionedwith respect to the transducer at a predetermined angle in a secondplane, the predetermined angle being about 70-110 degrees; and at leasttwo elongate mounting pins carried in a spaced relations each elongatemounting pin connecting the transducer to the signal conditioner, thuspositioning the first plane at the predetermined angle to the secondplane.
 2. A compact sensing apparatus as defined in claim 1, furthercomprising a plurality of bonding pads formed on the same semiconductorwafer for each of the transducer and the signal conditioner for bondingthe transducer and the signal conditioner to thereby provide aconductive path between the transducer and the signal conditioner.
 3. Acompact sensing apparatus comprising: a transducer formed from asemiconductor wafer positioned in a first plane; a signal conditionerformed from a semiconductor wafer, electrically connected to thetransducer, and positioned with respect to the transducer at apredetermined angle in a second plane, the predetermined angle beingless than 180 degrees; and at least two elongate mounting pins carriedin a spaced relation, each elongate mounting pin connecting thetransducer to the signal conditioner, thus positioning the first planeat the predetermined angle to the second plane.
 4. A compact sensingapparatus as defined in claim 3, wherein the transducer and the signalconditioner are formed from the same semiconductor wafer, and theapparatus further comprising a plurality of bonding pads formed on thesame semiconductor wafer for each of the transducer and the signalconditioner for bonding the transducer and the signal conditioner tothereby provide a conductive path between the transducer and the signalconditioner.
 5. A compact sensing apparatus comprising: a transducerformed from a semiconductor wafer positioned in a first plane, thetransducer having a substantially planar outer surface to moresensitively sense a field having flux lines extending substantiallyperpendicular to the planar outer surface; a signal conditioner formedfrom the same semiconductor wafer in electrical communication with thetransducer, and positioned with respect to the transducer at apredetermined angle in a second plane, the predetermined angle beingless than 180 degrees; at least one conductor electrically connected tothe signal conditioner to connect the signal conditioner to externalsensor monitoring equipment; and at least two elongate mounting pinscarried in a spaced relation, each elongate mounting pin connecting thetransducer to the signal conditioner, thus positioning the first planeat the predetermined angle to the second plane.
 6. A compact sensingapparatus as defined in claim 1, wherein each elongate mounting pinincludes a first and second pin portions forming the predetermined angletherebetween, the first pin portion securing the transducer thereto andthe second pin portion securing the signal conditioner thereto forpositioning the first plane at the predetermined angle to the secondplane.
 7. A compact sensing apparatus as defined in claim 3, whereineach elongate mounting pin includes a first and second pin portionsforming the predetermined angle therebetween, the first pin portionsecuring the transducer thereto and the second pin portion securing thesignal conditioner thereto for positioning the first plane at thepredetermined angle to the second plane.
 8. A compact sensing apparatusas defined in claim 5, wherein each elongate mounting pin includes afirst and second pin portions forming the predetermined angletherebetween, the first pin portion securing the transducer thereto andthe second pin portion securing the signal conditioner thereto forpositioning the first plane at the predetermined angle to the secondplane.